The search for life on Mars has been one of humanity’s most enduring and exciting quests. Ever since we first saw the Red Planet, we’ve wondered whether it ever harbored life, and if so, what kind of life forms they were.
One of the most promising places to look for signs of ancient life on Mars is Jezero Crater, a 28-mile-wide depression that was once a lake billions of years ago.
Scientists believe this lake could be a suitable environment for microbial life to flourish, and that some of these microbes have left fossils in the rocks and sediments.
That is why NASA sent its Perseverance rover to the Jezero Crater in 2021, with the main goal of collecting and storing samples that could contain traces of past life. Perseverance has been busy exploring the crater, drilling into rocks and storing the samples in sealed tubes.
But how do we know that these samples are worth bringing back to Earth? How can we be sure that the Jezero crater was indeed a habitable place in the past?
Well, Perseverance has another tool to help answer these questions: a ground-penetrating radar (GPR) that can peer beneath the surface and reveal the hidden layers of history.
The GPR works by emitting radio waves and measuring how they bounce back from different materials. By analyzing the reflections, scientists can create a map of the subsurface structure and composition.
Recently, Perseverance used its GPR to scan a region of the Jezero Crater called “Citadelle,” where it had collected some of its samples. The results were stunning: the GPR discovered multiple layers of sediment that indicated Citadelle was once part of an ancient lake bed.
This is an important discovery because it confirms that the Jezero Crater was indeed filled with water in the past, and that the samples collected by Perseverance could potentially contain fossil evidence of ancient life.
However, there is still a long way to go before we can verify this hypothesis. The samples collected by Perseverance are not enough to conclusively prove the existence of life on Mars. They need to be analyzed in more detail by advanced instruments on Earth.
That’s why NASA and ESA are planning a bold and ambitious mission to bring the samples back home. This mission involves several steps and spacecraft, and will take several years to complete.
The first step is to send ESA’s Sample Retrieval Lander (SRL) to the Jezero crater, which will carry a small rover named Fetch. Fetch will drive around the crater and collect the sample tubes left behind by Perseverance. They are then returned to the SRL, which places them in orbit.
The second step is to send another spacecraft, the Earth-return orbiter (ERO), which will rendezvous with the sample container in orbit and capture it. The emergency response team will then return to Earth and release the container into the atmosphere, where it will land safely with a parachute.
The final step is to retrieve the container and transport it to a secure laboratory, where scientists will carefully open it and examine the samples inside. This will be a historic moment because it will be the first time we have brought material from another planet.
Analyzing the samples could take years or even decades, but it could also revolutionize our understanding of Mars and its history. It could reveal whether Mars ever had life, and if so, what types of life forms they were. It could also shed light on how life originated and evolved in our solar system, and whether we are alone in the universe.
The search for life on Mars is not over yet. It’s just beginning.
The researchers published their findings in the journal on January 26 Scientific progress.
